Exploring Inflationary Initial State With Large Scale Structure Observations

TL;DR

This paper examines how large scale structure observations can constrain the initial state of inflation, finding that non-Bunch-Davies states are still compatible with current data.

Contribution

It introduces a model-independent framework for initial states and applies Bayesian analysis to LSS data to constrain inflationary initial conditions.

Findings

Non-Bunch-Davies initial states are compatible with current LSS data.

Constraints on initial vacuum states are derived from SDSS-DR7 and WiggleZ surveys.

The analysis supports the viability of alternative initial states in inflation.

Abstract

We investigate for possible constraints on inflationary initial state from Large Scale Structure (LSS) observations. Using a model-independent framework, we build the template for the generic initial state and construct the matter power spectrum through time evolution of the primordial power spectrum. We then make use of the LSS data separately from the Sloan Digital Sky Survey - Data Release 7 (SDSS-DR7) sample of Luminous Red Galaxies (LRG) and WiggleZ Dark Energy Survey, and explore the plausible constraints on initial vacuum by applying Bayesian parameter estimation method with Markov Chain Monte Carlo (MCMC) simulation. Our analysis reveals that, along with the usual Bunch-Davies vacuum, non-Bunch-Davies initial states are also fairly allowed so far as present LSS data is concerned.